Intramedullary spinal cord gangliogliomas are rare tumors composed of glial components and ganglion cells. These gangliogliomas are generally considered as slow-growing tumors, corresponding histologically to WHO grade I or II. There are few reports of large case series of intramedullary spinal cord gangliogliomas from a single center. We retrospectively reviewed a consecutive series of 18 patients with pathologically diagnosed ganglioglioma. Clinical manifestations, radiological features, treatment and follow-up data, and concomitant scoliosis were investigated. The mean age at diagnosis was 27.5 years, with a slight female predominance. The primary clinical symptoms were sensorimotor deficits. Magnetic resonance (MR) imaging manifestations varied considerably. Some associated, but not necessary, features were found, such as young age at onset, large tumor dimension, and bony changes. Scoliosis was observed in seven patients. Remnant tumor progression was observed in five patients during the follow-up period, and no deaths occurred. The last neurological evaluation showed functional improvement from preoperative status in five patients. Differential diagnosis of ganglioglioma based on MR images alone is challenging, but the combination of some characteristic features can be helpful. An accurate diagnosis of ganglioglioma depends on pathological criteria. Despite the benign course of ganglioglioma, considerable growth may affect its resectability and prognosis. The extent of resection should be meticulously planned, and the potential risk of recurrence and neurological deterioration should be evaluated. The concomitant scoliosis is noteworthy.